1 /* 2 i2c Support for Apple SMU Controller 3 4 Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp. 5 <benh@kernel.crashing.org> 6 7 This program is free software; you can redistribute it and/or modify 8 it under the terms of the GNU General Public License as published by 9 the Free Software Foundation; either version 2 of the License, or 10 (at your option) any later version. 11 12 This program is distributed in the hope that it will be useful, 13 but WITHOUT ANY WARRANTY; without even the implied warranty of 14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 GNU General Public License for more details. 16 17 */ 18 19 #include <linux/module.h> 20 #include <linux/kernel.h> 21 #include <linux/types.h> 22 #include <linux/i2c.h> 23 #include <linux/device.h> 24 #include <linux/platform_device.h> 25 #include <linux/of_irq.h> 26 #include <asm/prom.h> 27 #include <asm/pmac_low_i2c.h> 28 29 MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); 30 MODULE_DESCRIPTION("I2C driver for Apple PowerMac"); 31 MODULE_LICENSE("GPL"); 32 33 /* 34 * SMBUS-type transfer entrypoint 35 */ 36 static s32 i2c_powermac_smbus_xfer( struct i2c_adapter* adap, 37 u16 addr, 38 unsigned short flags, 39 char read_write, 40 u8 command, 41 int size, 42 union i2c_smbus_data* data) 43 { 44 struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); 45 int rc = 0; 46 int read = (read_write == I2C_SMBUS_READ); 47 int addrdir = (addr << 1) | read; 48 int mode, subsize, len; 49 u32 subaddr; 50 u8 *buf; 51 u8 local[2]; 52 53 if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) { 54 mode = pmac_i2c_mode_std; 55 subsize = 0; 56 subaddr = 0; 57 } else { 58 mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub; 59 subsize = 1; 60 subaddr = command; 61 } 62 63 switch (size) { 64 case I2C_SMBUS_QUICK: 65 buf = NULL; 66 len = 0; 67 break; 68 case I2C_SMBUS_BYTE: 69 case I2C_SMBUS_BYTE_DATA: 70 buf = &data->byte; 71 len = 1; 72 break; 73 case I2C_SMBUS_WORD_DATA: 74 if (!read) { 75 local[0] = data->word & 0xff; 76 local[1] = (data->word >> 8) & 0xff; 77 } 78 buf = local; 79 len = 2; 80 break; 81 82 /* Note that these are broken vs. the expected smbus API where 83 * on reads, the length is actually returned from the function, 84 * but I think the current API makes no sense and I don't want 85 * any driver that I haven't verified for correctness to go 86 * anywhere near a pmac i2c bus anyway ... 87 * 88 * I'm also not completely sure what kind of phases to do between 89 * the actual command and the data (what I am _supposed_ to do that 90 * is). For now, I assume writes are a single stream and reads have 91 * a repeat start/addr phase (but not stop in between) 92 */ 93 case I2C_SMBUS_BLOCK_DATA: 94 buf = data->block; 95 len = data->block[0] + 1; 96 break; 97 case I2C_SMBUS_I2C_BLOCK_DATA: 98 buf = &data->block[1]; 99 len = data->block[0]; 100 break; 101 102 default: 103 return -EINVAL; 104 } 105 106 rc = pmac_i2c_open(bus, 0); 107 if (rc) { 108 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc); 109 return rc; 110 } 111 112 rc = pmac_i2c_setmode(bus, mode); 113 if (rc) { 114 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n", 115 mode, rc); 116 goto bail; 117 } 118 119 rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len); 120 if (rc) { 121 if (rc == -ENXIO) 122 dev_dbg(&adap->dev, 123 "I2C transfer at 0x%02x failed, size %d, " 124 "err %d\n", addrdir >> 1, size, rc); 125 else 126 dev_err(&adap->dev, 127 "I2C transfer at 0x%02x failed, size %d, " 128 "err %d\n", addrdir >> 1, size, rc); 129 goto bail; 130 } 131 132 if (size == I2C_SMBUS_WORD_DATA && read) { 133 data->word = ((u16)local[1]) << 8; 134 data->word |= local[0]; 135 } 136 137 bail: 138 pmac_i2c_close(bus); 139 return rc; 140 } 141 142 /* 143 * Generic i2c master transfer entrypoint. This driver only support single 144 * messages (for "lame i2c" transfers). Anything else should use the smbus 145 * entry point 146 */ 147 static int i2c_powermac_master_xfer( struct i2c_adapter *adap, 148 struct i2c_msg *msgs, 149 int num) 150 { 151 struct pmac_i2c_bus *bus = i2c_get_adapdata(adap); 152 int rc = 0; 153 int read; 154 int addrdir; 155 156 if (num != 1) { 157 dev_err(&adap->dev, 158 "Multi-message I2C transactions not supported\n"); 159 return -EOPNOTSUPP; 160 } 161 162 if (msgs->flags & I2C_M_TEN) 163 return -EINVAL; 164 read = (msgs->flags & I2C_M_RD) != 0; 165 addrdir = (msgs->addr << 1) | read; 166 167 rc = pmac_i2c_open(bus, 0); 168 if (rc) { 169 dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc); 170 return rc; 171 } 172 rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std); 173 if (rc) { 174 dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n", 175 pmac_i2c_mode_std, rc); 176 goto bail; 177 } 178 rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len); 179 if (rc < 0) { 180 if (rc == -ENXIO) 181 dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n", 182 addrdir & 1 ? "read from" : "write to", 183 addrdir >> 1, rc); 184 else 185 dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n", 186 addrdir & 1 ? "read from" : "write to", 187 addrdir >> 1, rc); 188 } 189 bail: 190 pmac_i2c_close(bus); 191 return rc < 0 ? rc : 1; 192 } 193 194 static u32 i2c_powermac_func(struct i2c_adapter * adapter) 195 { 196 return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE | 197 I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA | 198 I2C_FUNC_SMBUS_BLOCK_DATA | I2C_FUNC_I2C; 199 } 200 201 /* For now, we only handle smbus */ 202 static const struct i2c_algorithm i2c_powermac_algorithm = { 203 .smbus_xfer = i2c_powermac_smbus_xfer, 204 .master_xfer = i2c_powermac_master_xfer, 205 .functionality = i2c_powermac_func, 206 }; 207 208 209 static int i2c_powermac_remove(struct platform_device *dev) 210 { 211 struct i2c_adapter *adapter = platform_get_drvdata(dev); 212 213 i2c_del_adapter(adapter); 214 memset(adapter, 0, sizeof(*adapter)); 215 216 return 0; 217 } 218 219 static u32 i2c_powermac_get_addr(struct i2c_adapter *adap, 220 struct pmac_i2c_bus *bus, 221 struct device_node *node) 222 { 223 const __be32 *prop; 224 int len; 225 226 /* First check for valid "reg" */ 227 prop = of_get_property(node, "reg", &len); 228 if (prop && (len >= sizeof(int))) 229 return (be32_to_cpup(prop) & 0xff) >> 1; 230 231 /* Then check old-style "i2c-address" */ 232 prop = of_get_property(node, "i2c-address", &len); 233 if (prop && (len >= sizeof(int))) 234 return (be32_to_cpup(prop) & 0xff) >> 1; 235 236 /* Now handle some devices with missing "reg" properties */ 237 if (!strcmp(node->name, "cereal")) 238 return 0x60; 239 else if (!strcmp(node->name, "deq")) 240 return 0x34; 241 242 dev_warn(&adap->dev, "No i2c address for %s\n", node->full_name); 243 244 return 0xffffffff; 245 } 246 247 static void i2c_powermac_create_one(struct i2c_adapter *adap, 248 const char *type, 249 u32 addr) 250 { 251 struct i2c_board_info info = {}; 252 struct i2c_client *newdev; 253 254 strncpy(info.type, type, sizeof(info.type)); 255 info.addr = addr; 256 newdev = i2c_new_device(adap, &info); 257 if (!newdev) 258 dev_err(&adap->dev, 259 "i2c-powermac: Failure to register missing %s\n", 260 type); 261 } 262 263 static void i2c_powermac_add_missing(struct i2c_adapter *adap, 264 struct pmac_i2c_bus *bus, 265 bool found_onyx) 266 { 267 struct device_node *busnode = pmac_i2c_get_bus_node(bus); 268 int rc; 269 270 /* Check for the onyx audio codec */ 271 #define ONYX_REG_CONTROL 67 272 if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) { 273 union i2c_smbus_data data; 274 275 rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ, 276 ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA, 277 &data); 278 if (rc >= 0) 279 i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46); 280 281 rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ, 282 ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA, 283 &data); 284 if (rc >= 0) 285 i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47); 286 } 287 } 288 289 static bool i2c_powermac_get_type(struct i2c_adapter *adap, 290 struct device_node *node, 291 u32 addr, char *type, int type_size) 292 { 293 char tmp[16]; 294 295 /* Note: we to _NOT_ want the standard 296 * i2c drivers to match with any of our powermac stuff 297 * unless they have been specifically modified to handle 298 * it on a case by case basis. For example, for thermal 299 * control, things like lm75 etc... shall match with their 300 * corresponding windfarm drivers, _NOT_ the generic ones, 301 * so we force a prefix of AAPL, onto the modalias to 302 * make that happen 303 */ 304 305 /* First try proper modalias */ 306 if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) { 307 snprintf(type, type_size, "MAC,%s", tmp); 308 return true; 309 } 310 311 /* Now look for known workarounds */ 312 if (!strcmp(node->name, "deq")) { 313 /* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */ 314 if (addr == 0x34) { 315 snprintf(type, type_size, "MAC,tas3001"); 316 return true; 317 } else if (addr == 0x35) { 318 snprintf(type, type_size, "MAC,tas3004"); 319 return true; 320 } 321 } 322 323 dev_err(&adap->dev, "i2c-powermac: modalias failure" 324 " on %s\n", node->full_name); 325 return false; 326 } 327 328 static void i2c_powermac_register_devices(struct i2c_adapter *adap, 329 struct pmac_i2c_bus *bus) 330 { 331 struct i2c_client *newdev; 332 struct device_node *node; 333 bool found_onyx = 0; 334 335 /* 336 * In some cases we end up with the via-pmu node itself, in this 337 * case we skip this function completely as the device-tree will 338 * not contain anything useful. 339 */ 340 if (!strcmp(adap->dev.of_node->name, "via-pmu")) 341 return; 342 343 for_each_child_of_node(adap->dev.of_node, node) { 344 struct i2c_board_info info = {}; 345 u32 addr; 346 347 /* Get address & channel */ 348 addr = i2c_powermac_get_addr(adap, bus, node); 349 if (addr == 0xffffffff) 350 continue; 351 352 /* Multibus setup, check channel */ 353 if (!pmac_i2c_match_adapter(node, adap)) 354 continue; 355 356 dev_dbg(&adap->dev, "i2c-powermac: register %s\n", 357 node->full_name); 358 359 /* 360 * Keep track of some device existence to handle 361 * workarounds later. 362 */ 363 if (of_device_is_compatible(node, "pcm3052")) 364 found_onyx = true; 365 366 /* Make up a modalias */ 367 if (!i2c_powermac_get_type(adap, node, addr, 368 info.type, sizeof(info.type))) { 369 continue; 370 } 371 372 /* Fill out the rest of the info structure */ 373 info.addr = addr; 374 info.irq = irq_of_parse_and_map(node, 0); 375 info.of_node = of_node_get(node); 376 377 newdev = i2c_new_device(adap, &info); 378 if (!newdev) { 379 dev_err(&adap->dev, "i2c-powermac: Failure to register" 380 " %s\n", node->full_name); 381 of_node_put(node); 382 /* We do not dispose of the interrupt mapping on 383 * purpose. It's not necessary (interrupt cannot be 384 * re-used) and somebody else might have grabbed it 385 * via direct DT lookup so let's not bother 386 */ 387 continue; 388 } 389 } 390 391 /* Additional workarounds */ 392 i2c_powermac_add_missing(adap, bus, found_onyx); 393 } 394 395 static int i2c_powermac_probe(struct platform_device *dev) 396 { 397 struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev); 398 struct device_node *parent = NULL; 399 struct i2c_adapter *adapter; 400 const char *basename; 401 int rc; 402 403 if (bus == NULL) 404 return -EINVAL; 405 adapter = pmac_i2c_get_adapter(bus); 406 407 /* Ok, now we need to make up a name for the interface that will 408 * match what we used to do in the past, that is basically the 409 * controller's parent device node for keywest. PMU didn't have a 410 * naming convention and SMU has a different one 411 */ 412 switch(pmac_i2c_get_type(bus)) { 413 case pmac_i2c_bus_keywest: 414 parent = of_get_parent(pmac_i2c_get_controller(bus)); 415 if (parent == NULL) 416 return -EINVAL; 417 basename = parent->name; 418 break; 419 case pmac_i2c_bus_pmu: 420 basename = "pmu"; 421 break; 422 case pmac_i2c_bus_smu: 423 /* This is not what we used to do but I'm fixing drivers at 424 * the same time as this change 425 */ 426 basename = "smu"; 427 break; 428 default: 429 return -EINVAL; 430 } 431 snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename, 432 pmac_i2c_get_channel(bus)); 433 of_node_put(parent); 434 435 platform_set_drvdata(dev, adapter); 436 adapter->algo = &i2c_powermac_algorithm; 437 i2c_set_adapdata(adapter, bus); 438 adapter->dev.parent = &dev->dev; 439 440 /* Clear of_node to skip automatic registration of i2c child nodes */ 441 adapter->dev.of_node = NULL; 442 rc = i2c_add_adapter(adapter); 443 if (rc) { 444 printk(KERN_ERR "i2c-powermac: Adapter %s registration " 445 "failed\n", adapter->name); 446 memset(adapter, 0, sizeof(*adapter)); 447 return rc; 448 } 449 450 printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name); 451 452 /* Use custom child registration due to Apple device-tree funkyness */ 453 adapter->dev.of_node = dev->dev.of_node; 454 i2c_powermac_register_devices(adapter, bus); 455 456 return 0; 457 } 458 459 static struct platform_driver i2c_powermac_driver = { 460 .probe = i2c_powermac_probe, 461 .remove = i2c_powermac_remove, 462 .driver = { 463 .name = "i2c-powermac", 464 .bus = &platform_bus_type, 465 }, 466 }; 467 468 module_platform_driver(i2c_powermac_driver); 469 470 MODULE_ALIAS("platform:i2c-powermac"); 471